As a system for restraining an automobile occupant at the time of a collision, there has been proposed an apparatus that raises a front portion of a seat cushion upward during a vehicle collision to prevent a so-called submarine phenomenon. Specifically, a submarine phenomenon can occur when an occupant wearing a seatbelt slips through a space below a lap belt during a frontal collision. For example, Japanese Unexamined Patent Application Publication No. 2002-79861 discloses a vehicle seat in which the front portion of the seat cushion can be pushed upward by an airbag. In this disclosure, an inflator is set on a seat pan that is located below a thigh-supporting section of the seat cushion.
Known types of occupant restraining apparatuses are, for example, a so-called air belt apparatus having an airbag attached to a part of a seatbelt (e.g. a shoulder belt portion and/or a lap belt portion) or an airbag constituting a part of a seatbelt, and a so-called inflatable seatbelt apparatus.
Japanese Unexamined Patent Application Publication No. 2002-145002 discloses an occupant restraining apparatus that restrains an occupant by inflating three components, which are a seat bag provided at a front portion of a seat cushion, and a shoulder belt portion and a lap belt portion of an air belt. In this disclosure, the seat bag, the shoulder belt portion, and the lap belt portion are inflated by means of a single inflator.
In the occupant restraining apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2002-145002, the inflatable shoulder belt portion and the inflatable lap belt portion have one of their ends connected to separate tongues. The shoulder belt portion and the lap belt portion are latched to a buckle device by means of their tongues. The buckle device and the tongues are provided with gas supply paths for supplying the gas from the inflator to the shoulder belt portion and the lap belt portion. This inflator is provided at a left side of a seat frame.
Japanese Unexamined Patent Application Publication No. 2000-25545 describes an air belt apparatus in which a bag is inflatable by means of gas from an inflator. In this air belt apparatus, the inflator is provided at an air-belt anchor.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-79861
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2000-25545
Patent Document 3: Japanese Unexamined Patent Application Publication No. 2002-145002
If an inflator is to be disposed above a seat pan, the thickness of the seat cushion at that section will need to be reduced, and therefore, the seat cushion will become uncomfortable to sit in.
If an inflator is to be provided alongside a side of a seat frame, it will become necessary to make an installation space for the inflator alongside the seat frame, leading to reduced design flexibility of the seat.